Hello Nazrin,
I'm a little puzzled by your statement:
"Its like jumps off the to the SAP_APPL,602 without applying remaining patches in SAP_APPL,600."
I understand your business need SAP_APPL 600; however every time you upgrade an application there is an equivalency of SPs levels that might be helpful for your case. Please check note #1165437 and #1297231, as well as the following discussion:
http://scn.sap.com/thread/1403187
Best regards,
Tomas Black